Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 779

Table Data Processing Instructions
Ladder Symbol
Variations
Applicable Program Areas
Operands
FCS(180)
C
R1
D
Variations Executed Each Cycle for ON Condition
Executed Once for Upward Differentiation
Executed Once for Downward Differentiation Not supported.
Immediate Refreshing Specification
Block program areas
OK
C and C+1: Control words
C specifies the number of units (bytes or words) to be used in the FCS calcu-
lation. (Bit 13 of C+1 determines whether bytes or words are being used.)
When bit 13 of C+1 has been set to 1, FCS(180) calculates the FCS value for
bytes of data. In this case, bit 12 determines whether the calculation starts
with the rightmost byte of R1 (bit 12 = 1) or the leftmost byte of R1 (bit 12 = 0).
C
C+1
Note C and C+1 must be in the same data area.
R1: First word in range
R1 specifies the first word in the range. The length of the range depends on
the number of units as well as the starting byte, if bytes are being used in the
calculation.
Note All of the words in the calculation range must be in the same data area.
C: First control word
R1: First word in range
D: First destination word
Step program areas
OK
15
Number of words/bytes in range
15 14 13 12 11
00 0000 0000 0000
Starting byte (Valid only when bit 13 is 1.)
0: Leftmost byte
1: Rightmost byte
Calculation units
0: Words
1: Bytes
0
15
Calculation range
R1
to
R1+(C units–1)
Section 3-17
FCS(180)
@FCS(180)
Not supported.
Subroutines Interrupt tasks
OK OK
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